Insertable check valve unit



March 8, 1966 R. F. SMITH INSERTABLE CHECK VALVE UNIT 2 Sheets-Sheet 1Original Filed Jan. 26, 1962 INVENTOR RUSSELL F. SMITH AGENT March 8,1966 R. F. SMITH INSERTABLE CHECK VALVE UNIT 2 Sheets-Sheet 2 OriginalFiled Jan. 26, 1962 INVENTOR RUSSELL F. SMITH AGENT United States PatentM 3,238,967 INSERTABLE CHECK VALVE UNIT Russell F. Smith, Ferguson, Mo.,assignor to ACF Industries, Incorporated, New York, N.Y., a corporationof New Jersey Original application .ian. 26, 1962, Ser. No. 169,012, newPatent No. 3,198,128, dated Aug. 3, 1965. Divided and this applicationApr. 24, 1964, Ser No. 362,279 1 Claim. (Ci. 137516.21)

This invention relates to pumps, and more particularly to a diaphragmpump of a type especially suitable for pumping automotive fuel to thecarburetor for an internal combustion engine, the diaphragm of the pumpbeing operable by a drive from the engine.

This application is a division of my copending application Serial No.169,012, filed January 26, 1962, now Patent No. 3,198,128, which in turnis a continuation-inpart of the copending application Serial No.122,025, filed July 5, 1961, now Patent No. 3,150,601.

One of the problems occurring with conventional diaphragm fuel pumps isthe problem of vaporization of fuel in the pump, with the attendantpossibility of interruption of flow of fuel to the carburetor, thisbeing customarily referred to as vapor lock. It will be understood thatthe fuel is highly volatile, having a tendency to pass from the liquidto the vapor state, which tendency is, of course, increased by heating.Since the fuel pump is conventionally mounted on the engine to be driventhereby, heat is transferred from the engine to the pump, and thereby tofuel in the pump. Unless this heat is effectively dissipated, vapor lockmay occur due to vaporization of fuel in the pump.

Accordingly, one of the objects of this invention is the provision of apump which, while being of simple, economical construction, is adaptedeffectively to dissipate heat from the pump so as effectively to reducethe tendency for volatilization of fuel in the pump, thereby to reducethe possibility of vapor lock. In general, this is accomplished byutilizing a pump body of thin-walled heat-conductive construction suchas to provide for transfer of heat outward through the wall of the bodyat such a rate as substantially to reduce the tendency for volatilzationof fuel within the body. The pump body is formed to provide a pumpingchamber and an intake cavity and a discharge body, and the pump includesa diaphragm closing the pumping chamber, an intake check valve in theintake cavity and a discharge check valve in the discharge cavity. Withthe body of thin-walled heat-conductive construction, heat iseffectively dissipated from the pumping chamber and from the intake anddischarge cavities, thereby maintaining fuel in the pump in a relativelycool state to reduce the tendency toward volatilization such as wouldotherwise be present. The pump body may be formed of relatively thinsheet metal, which provides for a simple economical construction whileat the same time providing for effective heat dissipation. Additionally,the outside surface of the body may be made heat-reflective to decreasethe absorption of heat by the body from ambient temperatures.

Further objects of the invention are the provision of means in thedischarge cavity or in both the discharge and intake cavities fordamping pulsations in the pressure of fuel delivered by the pump, so asto maintain a more uniform rate of delivery of fuel to the carburetor,and the provision of an improved check valve construction such as toavoid distortion of the check valves when they are assembled with thepump body, thereby to maintain the accuracy of the seats of the checkvalves. Other objects and features will be in part apparent and in partpointed out hereinafter.

The invention accordingly comprises the constructions Patented Mar. 8,lfifih hereinafter described, the scope of the invention being indicatedin the following claim.

In the accompanying drawings, in which several of various possibleembodiments of the invention are illustrated:

FIGURE 1 is a view in elevation illustrating a diaphragm pump of thisinvention in use on the engine of an automotive vehicle for pumping fuelfrom the fuel tank of the vehicle to the carburetor for the engine, thepump being of a type that may be referred to as an inverted pump;

FIGURE 2 is a vertical section of the pump shown in FIGURE 1;

FIGURE 3 is a bottom plan of FIGURE 2;

FIGURE 4 is an enlarged vertical cross section of a check valve used inthe pump;

FIGURE 5 is a bottom plan of the FIGURE 4 check valve;

FIGURE 6 is a fragmentary vertical cross section of a pump similar tothe FIGURE 2 and including a first type of pulsationdamping means;

FIGURE 7 is a fragmentary vertical cross sectional similar to FIGURE 6illustrating a second type of pulsation-damping means and alsoillustrating certain modifications in the pump construction;

FXGURE 8 is a half-section in perspective of a modified version of thepulsation-damping means of FIGURE 7; and

FIGURE 9 is a fragmentary vertical cross section similar to FIGURE 2illustrating another type of pulsationdamping means and alsoillustrating certain modifications in the pump construction.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

Referring to FIGURE 1 of the drawings, there is indicated at A anautomotive vehicle having an engine E on which is mounted a fuel pump Pof this invention. Fuel is delivered from fuel tank T of the vehiclethrough a line L1 to the fuel pump P and delivered by the latter througha line L2 to the carburetor C for the engine. The carburetor is mountedon the intake manifold of the engine, and an air filter F is shownmounted on the air horn of the carburetor.

As appears in FIGURE 1-3, pump P is a so-called inverted pump, i.e., itsinlet and outlet are located at the bottom of the pump. As shown indetail in FIGURES 2 and 3, pump P comprises a rocker arm housing 1 whichis open at one end (its left end as appears in FIGURE 2), this end beingreferred to as the inner end of the housing. This housing is ofgenerally rectangular form in vertical cross section and of decreasingheight from its inner end to its outer end (which is closed). At itsinner end it has a flange 3 for attaching it to the engine E. A rockerarm 5 is pivoted at 7 in the housing for rocking motion on a horizontalaxis transverse to the housing. Arm 5 has a portion 5a projecting out ofthe open inner end of the housing, and is biased to rock clockwise asviewed in FIGURE 2 by a spring 9. When the pump is mounted on theengine, the free end portion 5a of the rocker arm is engaged by anengine-driven eccentric or cam 11. On rotation of the cam through half arevolution from its FIGURE 2 position (wherein the low point of the camengages portion 5a of the rocker arm), the rocker arm is rockedcounterclockwise from its FIGURE 2 position against the bias of spring9. The latter is adapted to return the arm clockwise during thesucceeding half-revolution of the cam.

Extending downward from the rocker arm housing 1 at its outer end is ahollow conical pump head 13. An opening 15 is provided between theinterior of housing 1 and the hollow head T3 at the top of the latter.The conical head has an outwardly projecting comparatively thick flatflange 17 at the bottom. The bottom of this flange constitutes a seatingsurface for the margin of an annular diaphragm 19 consisting of arelatively thick disk of flexible fuel-resistant material, such as asuitable synthetic rubber, which when in unstressed condition, is flator substantially flat. The outer margin of the diaphragm is clampedagainst the bottom of flange 17 by a pump body 21 which, as illustratedin FIGURE 2, is of one-piece thin-walled sheet metal construction,formed of shallow cup shape, having a bottom or end wall 23 and aflaring, rounded annular peripheral wall 25 defining a pumping chamber26, with an outwardly extending annular flat flange 27 at the top ofwall 25, and a cylindric rim 29. The body 21 is maintained in assemblywith head 13 by spinning the rim 29 over on flange 17 of the head asindicated at 31, with the margin of the diaphragm clamped between fiange17 and flange 27 under suflicient pressure to provide a fuel-tight sealall around the margin of the diaphragm.

The diaphragm is adapted to be pulled or flexed upward by adiaphragm-actuating rod 33 and to be flexed downward by a spring 35. Rod33 extends upward through head 13 and through the opening 15 at the topof the head into the rocker arm housing 1. The rocker arm 5 has a slot37 at its end in housing 1 receiving the rod 33. The latter has a collar39 at its upper end engageable by this end of the arm 5. The rod extendsslidably through an oil seal and rod guide 41 held in an annular recessat the top of the head 13 by the reaction on a seal retainer ring 43 ofthe spring 35, this spring being a coil compression spring surroundingthe rod. The diaphragm is mounted on the lower end of the rod 33 betweena pair of circular plates 45 and 47, plate 45 being the upper plate andplate 47 the lower plate. The upper plate is formed with an annularcorrugation or rib 49 forming a seat for confining the lower end ofspring 35. The upper plate is of larger diameter than the lower plateand the margin of the upper plate which overhangs the lower plate isflared outward and downward to provide a rim 51 constraining thediaphragm to have an annular, free, nonreversing loop 53. The lowerplate has a curved rim 55 engaging the loop. In the downward position ofthe diaphragm illustrated in FIGURE 2, the outside of the loop engagesthe rounded flaring wall 25 of the pump body 21. When arm 5 is rockedcounterclockwise by cam 11, it lifts the rod and pulls the diaphragmupward. This loads the spring 35. Then when arm 5 rocks clockwise,spring 35 is adapted to drive the diaphragm and rod downward.

The sheet metal pump body 27 is formed with two integral deepdrawnrounded-bottom cylindrical cupshaped projections 57 and 59 extendingdownward from the bottom wall 23 of body 21 on opposite sides of thecenter of the bottom wall. Projection 57 defines an inlet passage orintake cavity 61 and projection 59 defines an outlet passage ordischarge cavity 63. An inlet nipple 65 is provided at the lower end ofprojection 57, and an outlet nipple 67 is provided at the lower end ofprojection 59. In FIGURE 2, inlet nipple 65 is shown as a straightnipple, and outlet nipple 67 is shown as an elbow nipple. It will beunderstood that, in the installation shown in FIGURE 1, supply line L1is connected to inlet nipple 65 and discharge line L2 is connected tooutlet nipple 67.

The nipples 65 and 67 are fixed to the respective deepdrawn projections57 and 59 by inserting the respective collared ends 66 and 68 into acentral aperture in the bottom of the respective projections 57 and 59and swaging the metal of the projections tightly against the nippleends, as shown to form a fuel tight seal. The collared nipple ends 66and 68 each have grooves formed in the surface of the collars so thatthe swaged metal is pressed into the grooves to prevent a rotationdisplacement of the nipples. The sheet metal construction of the pumpthus lends itself to a universal adjustment of the nipple 67, for

example, in 360 to accommodate any required directional departure of theinlet fuel line L2. In a similar manner nipple 65 may also be formedwith an elbow to accommodate any directional approach of inlet line L1.This universal adjustability of the nipples 65 and 67 provides aflexibility of use with different engine arrangements, which is notavailable in pumps fabricated from castings.

An intake check valve 69 is provided in the intake cavity 61 and adischarge check valve 71 is provided in the discharge cavity 63. Nipple65 provides for connection of supply line L1 to intake cavity 61upstream from the intake check valve 69 and nipple 67 provides forconnection of discharge line L2 to discharge cavity 63 downstream fromthe discharge check valve 71. These check valves are of identicalconstruction. As shown in FIGURES 4 and 5, each check valve comprises acircular sheet metal valve seat 73 having a cylindric rim 75 sized for apress fit in either cavity 61 or cavity 63, as the case may be. Seat 73has a central hole 77 with an annular boss 79 around the hole extendingin the same direction as the rim 75. Surrounding the central hole is aseries of ports 81 arranged in a circle around the center hole. Thedimension of each of these ports as measured along the stated circle isless than the distance measured radially of the seat 73 from theperiphery of the center hole 77 to the periphery of the seat 73. Moreparticularly, the ports are circular holes of smaller diameter than thecenter hole. The are equally and closely spaced around the stated circleat intervals such as to leave spokelike portions 82 of the valve seat 73between the ports with these spokelike portions narrower than thediameter of the ports. Seat 73 is preferably dished inwardly to a slightextent in the direction in which rim 75 and boss 79 project therefrom(i.e., downwardly dished as viewed in FIGURE 4). This dishing may be ofthe order of 1 /2 for example. Fitted in the boss 79 is a hollow sheetmetal stem 83 which is closed at its lower end as indicated at 85 inFIGURE 4. Stem 83 has an apertured mushroom head 87 at its other endconstituting a spring seat. A ring-shaped disk valve member 89, whichmay be made of a suitable fuel-resistant synthetic rubber for cushionedsealing is slidable on the stem and is biased toward engagement with thevalve seat by a coil compression spring 91 surrounding the stem andreacting from the head 87. In assembling the stem with the valve seat,the stem 83 is pressed in the central hole 77 in the valve seat and theclosed end of the stem is deformed as indicated at 93 to lock the stemin the seat and seal the central hole.

The intake check valve 69 is pressed in the intake cavity 61 with itsstem 83 extending upward and the discharge check valve 71 is pressed inthe discharge cavity 63 with its stem extending downward (see FIGURE 2).It has been found that, with the ports in the valve seat formed asherein described, rather than being formed as relatively long slots inthe valve seat, stresses such as would cause distortion of the valveseats during the operation of pressing the seats into the cavities areavoided, and the original accuracy of the seats is preserved. At thesame time, the total port area is adequate for flow of fuel.

In the operation of the pump shown in FIGURE 2, diaphragm 19 is flexedup and down by the action of arm 11 and spring 35. On an upward(suction) stroke of the diaphragm, the intake check valve 69 opens andthe discharge check valve 71 closes, and fuel is drawn into the pumpingchamber 26 below the diaphragm. On a downward (discharge) stroke of thediaphragm, the intake check valve 69 closes and the discharge checkvalve 71 opens, and fuel is forced out through line L2 to thecarburetor. Since the pump body 21 is formed of sheet metal, it is ofthin-walled heat-conductive construction such as to provide for transferof heat outward there through at such a rate as substantially to reducethe tendency for volatilization of fuel within the body, therebyreducing the possibility of vapor lock. In this respect,

it will be observed that heat transmission occurs not only through walls23 and 25 of pumping chamber 26 but also through the walls and bottomsof projections 57 and 59, all of which are thin-walled, so that heat isdissipated at a relatively rapid rate. The rate may be increased bymaking the outer surface of the pump body heat-reflective, as by brightzinc plating of the exterior of the pump body. With such plating, heatis reflected from the body for cooler operation of the pump andincreased transmission of heat from fuel in the pump body to theexterior.

Making the pump body of sheet metal not only provides a thin-walledconstruction for effective heat dissipation, but also provides aneconomical construction, the pump body itself being economical tomanufacture and economical to assemble with the rocker arm housing 1,the assembly operation simply involving the spinning over of rim 29 ofthe pump body on flange 17 of the head 13. A typical pump body having adiameter (measured at rim 29) of three and one-half inches may be madeof suitable steel plate 0.035 inch thick, for example. In general, theadvantages of the invention may be attained with a pump body having awall thickness less than 0.050 inch.

FIGURE 6 illustrates a pump similar to that shown in FIGURE 2 providedwith means for damping pulsations in pressure of fuel delivered by thepump so as to maintain a more uniform rate of delivery of fuel to thecarburetor. As shown in FIGURE 6, the cup-shaped projections of the pumpbody 21 are drawn deeper than in FIGURE 2, and are designated 57a and59a. In each cup is pressfitted a partition 101 having a central hole103 and a circular series of ports 105 around the central hole 103. Theportion of the partition around the center hole is cupped as indicatedat 107 to form a seat for a hollow resilient compressible ball 109 whichmay be made, for example, of a suitable fuel-resistant synthetic rubber.In the intake cup 57a the partition is arranged with seat 107 extendingupward and ball 109 below the partition. In the discharge cup 59a, thepartition is arranged with seat 107 extending downward and ball 109above the partition. The hollow resilient compressible balls 109 actlike air chambers or air domes to damp pulsations of pressure of fuel inthe intake and discharge cavities by contraction and expansion thereof,and tend to equalize pressure of fuel delivered to the carburetor.

FIGURE 7 illustrates a modification in which the cupshaped projectionsof the pump body 21 are constituted by separately formed cup members 57band 59b. Each of these has an outwardly extending rim 111 at its upperend and extends down through an opening 113 provided in the bottom wall23 of the pump body, the rims engaging the bottom wall 23 and beingsuitably soldered thereto. This three-piece type of construction for thepump body 21 has the advantage over the one-piece type of pump bodyshown in FIGURE 6, for example, in that, for a given cup height, itpermits the cups to be arranged closer together, as may be desirable. Inthis respect, it will be observed that with deep-drawn integral cups asin FIG- URE 6, it is necessary that the cups be relatively widely spacedto permit deep drawing.

FIGURE 7 also illustrates another type of pulsation damping meanscomprising an annular hollow resiliently compressible member 121 axiallypositioned in each projection 57b and 59b, each of these members beingmade, for example, of a suitable fuel-resistant synthetic rubber. Thecentral passages 125 through these members provide for flow of fuel, andpulsations are damped by contraction and expansion of the members, whichact like air chambers or air domes.

FIGURE 8 illustrates a modification of the pulsation clamping members ofFIGURE 7, showing an annular re siliently compressible member 121a madeof closed-cell foam rubber of a fuel-resistant variety. Such members maybe conveniently obtained by segmenting an extruded tube of theclosed-cell foam rubber material. They are placed in cups 57b and 59b inthe same manner as members 121 shown in FIGURE 7.

FIGURE 9 illustrates another arrangement for pulsation damping on thedischarge side of the pump only. As shown therein, the intake cup,designated 57c, is a relatively short cup (as in FIG. 2), formed as aseparate piece and soldered to the pump body as in FIGURE 7. Thedischarge cup comprises a shell 131 having a cylindric upper end portion133 received in an opening in the bottom wall 23 of pump body 21 in thesame manner as in FIGURE 7, and a flaring lower portion 135. Thedischarge check valve 71 is pressed into the cylindric portion 133. Theflaring lower portion has an outwardly projecting flat annular flange137 at its lower end constituting a seating surface for a diaphragm 139made, for example, of a suitable fuel-resistant synthetic rubber. Theouter margin of the diaphragm is clamped against the bottom of flange137 by the rim 141 of an inverted dome 143 and the parts are held inassembly by spinning a rim 145 on flange 137 over on the rim 141 of thedome. The diaphragm 139 and the dome provide an air chamber 147 sealedofi from the shell 131, pulsations being damped by flexing of thediaphragm. The discharge nipple 149 is connected to shell 131 above thediaphragm 139.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim:

A check valve assembly for a pump having a wall formed with an opening,said valve assembly comprising a sheet metal valve seat having a portedvalve seat surface formed with a series of ports arranged in a circleand an outer marginal cylindrical rim generally at right angles from aface of said seat, a central opening formed in said seat defined by aflange extending in the direction of said rim, a valve retainerincluding a stem snugly fitted within said central opening and extendingbelow said flange and having an enlarged terminal portion below saidflange, said stem forming a closure for said central opening, said stemhaving a spring seat portion at the other end thereof, a disk valveslidably mounted on said stem between said spring seat portion and saidvalve seat, and a coil spring mounted around said stem between saidspring seat portion and said disk valve and biasing said disk valveagainst said ported valve seat surface.

References Cited by the Examiner UNITED STATES PATENTS 248,902 11/ 1881Whitman 137-454.2 1,976,464 10/1934 Shallenberg l37543.15 X 2,087,4178/1937 Peo 137543.15 X 2,531,532 11/1950 Rossman 13752S X 2,777,464 1/1957 Mosely 1375 16 2,803,265 8/1957 Coffey 137-543.l5

ISADOR WEIL, Primary Examiner.

WILLIAM F. ODEA, Examiner.

